I think the amount of pollution you are going to cause is tiny and insignificant in the big scale of things. I'm sure that most of the mechanics in the world would just open it up and let it go. (Though some might still charge you for evacuating and disposing
)
In some countries, they don't even put a pan under the car when they drain the oil.
It's good to be concerned about the environment, but it sounds like you have bigger problems to worry about.